This invention relates to bactericidal mixture control systems and in particular to such a system for coordinating the dispensing of liquid and bactericidal chemical pellets in a proper proportion.
Roof top water reservoirs are sometimes used to provide a desired water pressure as water is dispensed from the reservoir. The contents of the reservoirs must be open to the atmosphere to avoid creating a vacuum in the reservoir. Since they are open to the atmosphere, the water in them is susceptible to bacteria and algae growth so that a bactericidal chemical such as chlorine must be added to the water. It is important that the chemical be added to the water in the proper proportion to inhibit bacteria growth but maintain the water suitable for its intended purpose.
Prior art devices for controlling the concentration of chemicals in such mixtures have typically used flow measuring devices to measure the volume of water admitted to the reservoir. The appropriate quantity of chemical would then be added to the water, based on the measured volume of water. However, the flow measuring devices were expensive, trouble prone and not suitable for measuring relatively small flow rates.